Legal zm_420_breeze_b3a_pf crouch spot?

Saw this dude camping in poss a crouch spot. The player was able to hold off zombies pretty easily by themselves. Might be almost impossible if there were multiple players there. I know the depth isn't that great but w/it being on top of a shelf, might make it a crouch spot. May need to do some testing on it.

I watched a couple of ppl try to jump in there and the guy just kept shooting them back off the shelf, but i suppose it can be seen as one of those spots that if you're a good enough player you can get to it.